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granite4brains 01-31-15 02:18 PM

Shifting Adjustments Advice
 
Hi, newbie here to bicycle maintenance and had a couple quick questions on adjusting the shifting system.

I've got that "Zinn and the Fine Art of Bicycle Maintenance" and he covers the high and low gear limit screws, but seemingly only in the context of the chain staying on the chain rings while shifting.

However, I'm noticing the limit screws also seem crucial in keeping the chain from rubbing the front derailleur basket. (1) First question, is that correct?

My chain was rubbing the front derailleur basket when I was in the lowest hill climbing gears, so I believe I loosened the low gear limit screw, which moved the derailleur inwards. But, now it's rubbing if I am in the highest gear, or smallest cog, while still using the inner chain ring. I guess this is okay, because I could always shift to the outer chain ring and get the higher (faster) gears out there. I'd rather have the chain rub there, than on a hill climbing gear that is more crucial, right?

Anyhow, I guess my next questions are: (2) Any advice, or rules of thumb to follow when trying to get the chain to not rub and make a racket in certain gears? (3) Is there some better way to minimize the chain rubbing anywhere? (4) Maybe the derailleur isn't position right, or lined up with the rear cogs correctly?

Or, am I just going about this all wrong?

Thanks for any advice!

AnkleWork 01-31-15 02:24 PM


Originally Posted by granite4brains (Post 17517318)
. . . But, now it's rubbing if I am in the highest gear, or smallest cog, while still using the inner chain ring. . .

Cross chaining is bad.

granite4brains 01-31-15 02:28 PM


Originally Posted by AnkleWork (Post 17517333)
Cross chaining is bad.

So, I guess that means I am thinking about things right, by forgetting about the rubbing there and just using the outer chain ring as I get to higher gears, while making sure the hill climbing gear (inner chain ring, large cog) works good?

Or, put another way, maybe I shouldn't expect to be able to keep the chain free from rubbing the front derailleur basket everywhere, for example when cross chaining?

Guess that brings up another question ... is cross chaining as serious when you only have two chain rings on the front? (My old bike had three)

fietsbob 01-31-15 02:31 PM

A friction shifted FD allows you to re-center the cage after a rear shift changes the angle ..

STI wont. you just live with it then.

Learn what the actual Gear ratios are

once you get to the edge of the cluster in one chainring the Ratio overlap is probably where you are and
double shift to a similar ratio in the other Chainring

go to a gear calculator input the tooth counts and wheel size, Print up a chart , tape it on your bike.

granite4brains 01-31-15 02:34 PM


Originally Posted by fietsbob (Post 17517355)
A friction shifted FD allows you to re-center the cage after a rear shift changes the angle ..

STI wont. you just live with it then.

Hi fietsbob! Being a newbie I have no idea what that terminology means. What's the difference between friction shifted and STI? How do I tell which one I have? I'm guessing its STI, since I don't see a way to move the front derailleur cage, expect via the limit screws, which I guess brings me back to my original question.

fietsbob 01-31-15 02:37 PM

What components are on your Bike? STI is a trade name shimano invented

Shimano Front shifter goes ka thunk A B or C .. Double- A/B no adjustment other than the cage shape

thats why it looks so Funny

Old bikes and ones with bar end shifters the pull on the cable is the lever
its just friction vs the return spring on the orther end pulling back

Maybe a trip back to the shop where you bought the Bike* is in order so someone in the room can show you
what you ask about, here where no one can do hands on Demos.

or most others too .. if it's actually out of whack the cost to straighten it out wont be much.

hueyhoolihan 01-31-15 02:45 PM

chain noise due to excessive misalignment is not good, as far as i'm concerned, no matter it's provenance. it's a consequence of cassette width. fewer cogs will almost always provide some relief.

it's complicated and so there are too many exceptions on two vs three chainrings or even one chainring. but, in general the fewer chainrings the better. looked at from a larger perspective, a single speed bike with one chainrring and one cog and properly aligned will have no potential for cross-chaining. with every additional cog and additional chainring the potential for problems increases, IMO. :)

but more to the point, yes, it's expected that not all combinations of chainring/cog can be used. and if they are used the large/large and the small/small combinations may rub and make noise.

but i suppose now that electric assistance in shifting is deemed acceptable, we will have nested chainrings on the spindle and cogs on the freehub that pop out when needed and are always perfectly aligned. that holy grail should keep electronics and mechanical engineers busy in the bike industry for a decade or so, i think. :lol:

granite4brains 01-31-15 02:51 PM

Components wise, I just bought this guy:

Domane 4.5 - Trek Bicycle

[h=3]Drivetrain[/h] Shifters

Shimano Ultegra, 11 speed


Front derailleur

Shimano Ultegra, braze-on


Rear derailleur

Shimano Ultegra


Crank

Shimano RS500, 50/34 (compact)


Cassette

Shimano 105 11-32, 11 speed


Chain

Shimano 105

granite4brains 01-31-15 02:52 PM


Originally Posted by hueyhoolihan (Post 17517380)
chain noise due to excessive misalignment is not good, as far as i'm concerned, no matter it's provenance. it's a consequence of cassette width. fewer cogs will almost always provide some relief.

it's complicated and so there are too many exceptions on two vs three chainrings or even one chainring. but, in general the fewer chainrings the better. looked at from a larger perspective, a single speed bike with one chainrring and one cog and properly aligned will have no potential for cross-chaining. with every additional cog and additional chainring the potential for problems increases, IMO. :)

but more to the point, yes, it's expected that not all combinations of chainring/cog can be used. and if they are used there will be some noise.

Thanks, maybe I'm okay then, as the noise isn't super bad


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